1. Field of the Invention
The present invention relates to a shoe or boot which is provided in its inside portion with tank chambers which are filled with air, supporting and protecting a human foot from shocks imposed thereto.
2. Prior Art
Shoes have been proposed which are provided with a sensor for counting the number of steps taken by a user during walking or jogging to accumulate and indicate the number of steps taken within a certain time interval. Such shoes are disclosed, for example, in U.S. Pat. Nos. 4,651,446, 4,649,552, 4,578,769 and 4,571,680.
In sports, athlete's weight abruptly imposed to his foot could often be a cause of an injured foot. For lightening such burden imposed on foot, so called pump shoes are in use. The pump shoes are provided with tank chambers filled with air in its sole, instep and part in contact with a user's ankle respectively to prevent shocks from being applied to the user's foot and also to support his feet in a natural manner. By using the pump shoes, athlete can prevent his feet from being injured by shocks.
In the pump shoes, excessively low air pressure within the tank chambers provides neither a comfortable cushion nor a p63 sufficient support for his feet. On the contrary, excessively high air pressure within the tank chambers gives an oppressive feeling to the feet of the user, providing him with an uncomfortable feeling.
If the air pressure within the air chambers is adjustable, it will be convenient for the user to obtain preferable cushion and fitness for his feet.
The user, however, is required to determined the air pressure within the air chambers with his sense. Therefore, the user sometimes fills the air chambers with air excessively and has to release air from the air chambers to obtain proper air pressure, and on the contrary he releases air excessively from the air chambers and has to supply air into the air chambers again. In this manner, a time consuming and troublesome work is required to adjust air pressure within the air chambers to a level that is appropriate for the user.
Even though appropriate air pressure has been obtained, air can escape from the air chambers while the user is using the shoes. Therefore, the above air adjusting work has to be done several times to keep the air pressure at a proper level at all times.